Despite the fact that computer science (CS) is the driver of technological innovations across all disciplines and aspects of our lives, including participatory media, high school CS too commonly fails to incorporate the perspectives and concerns of low-income students of color. This article describes a partnership program -- Exploring Computer Science (ECS) -- that directly counters this problem in our nation's second largest school district. With a mission of democratizing CS learning, we argue that despite the constraints of working within public schools, it is imperative to do so. We discuss the ECS program based on inquiry, culturally relevant curriculum, and equity-oriented pedagogy. We describe two ECS-affiliated projects that highlight the importance of authorship, purpose, and agency for student learning and engagement: DietSens using mobile technology to study community health, and a project in which students create video games about social issues. Our work offers a counter-narrative to those who have written off the possibilities of working within public schools and a debunking of the too widespread myth within our educational system that females and students of color are inherently uninterested in rigorous CS learning. (Contains 11 notes and 3 tables.)